FractalParametric Overdrive

From the vendor

A versatile overdrive with a single-band parametric EQ, allowing adjustable boost or cut from 100 Hz to 4kHz.

The Fractal Parametric Overdrive is based on the Pearl OD-05 Over Drive, a curiously obscure effect from the early 80’s when Pearl briefly dipped into the guitar effects pedal business. The result was a line of very well-engineered pedals that unfortunately never got the attention they deserved.

Even 40 years later, this pedal still is relatively unknown. There are no commercial clones and it’s relatively unexplored in the DIY scene. But those who have played through one universally praise it for its tonal flexibility.

The OD-05 has a standard feedback-diode clipping stage like a Tube Screamer, but the magic is what comes in front of it: a parametric equalizer that allows either a cut or boost of up to 15dB in a range from 100 Hz to 4 KHz.

With this flexible preclipping EQ, you can get some incredible sounds out of it. You can crank the mids for a cocked-wah sound, or tune the circuit to enhance the resonant peak of your specific guitar and amp. You can even get a scooped-mids sound if that’s what you’re after, something that’s pretty rare in an overdrive.

The updated version of the Fractal includes one new feature: the fixed post-clipping treble cut can be dialed out for a slight treble boost. Since the parametric EQ only affects a single frequency band, this can allow for control over a second frequency, albeit with reduced functionality. Turned to zero, it’s identical to the stock circuit.

Note: This project uses a type of capacitor that has been temporarily discontinued by WIMA. Please see our news article about the issue and the substitution spreadsheet for project-specific recommendations. We are stocking a limited supply in the mean time. The build document has not yet been updated to reflect this.